libAACdec/src/channelinfo.cpp

   1
   2 /* -----------------------------------------------------------------------------------------------------------
   3 Software License for The Fraunhofer FDK AAC Codec Library for Android
   4
   5 © Copyright  1995 - 2013 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.
   6   All rights reserved.
   7
   8  1.    INTRODUCTION
   9 The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software that implements
  10 the MPEG Advanced Audio Coding ("AAC") encoding and decoding scheme for digital audio.
  11 This FDK AAC Codec software is intended to be used on a wide variety of Android devices.
  12
  13 AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient general perceptual
  14 audio codecs. AAC-ELD is considered the best-performing full-bandwidth communications codec by
  15 independent studies and is widely deployed. AAC has been standardized by ISO and IEC as part
  16 of the MPEG specifications.
  17
  18 Patent licenses for necessary patent claims for the FDK AAC Codec (including those of Fraunhofer)
  19 may be obtained through Via Licensing (www.vialicensing.com) or through the respective patent owners
  20 individually for the purpose of encoding or decoding bit streams in products that are compliant with
  21 the ISO/IEC MPEG audio standards. Please note that most manufacturers of Android devices already license
  22 these patent claims through Via Licensing or directly from the patent owners, and therefore FDK AAC Codec
  23 software may already be covered under those patent licenses when it is used for those licensed purposes only.
  24
  25 Commercially-licensed AAC software libraries, including floating-point versions with enhanced sound quality,
  26 are also available from Fraunhofer. Users are encouraged to check the Fraunhofer website for additional
  27 applications information and documentation.
  28
  29 2.    COPYRIGHT LICENSE
  30
  31 Redistribution and use in source and binary forms, with or without modification, are permitted without
  32 payment of copyright license fees provided that you satisfy the following conditions:
  33
  34 You must retain the complete text of this software license in redistributions of the FDK AAC Codec or
  35 your modifications thereto in source code form.
  36
  37 You must retain the complete text of this software license in the documentation and/or other materials
  38 provided with redistributions of the FDK AAC Codec or your modifications thereto in binary form.
  39 You must make available free of charge copies of the complete source code of the FDK AAC Codec and your
  40 modifications thereto to recipients of copies in binary form.
  41
  42 The name of Fraunhofer may not be used to endorse or promote products derived from this library without
  43 prior written permission.
  44
  45 You may not charge copyright license fees for anyone to use, copy or distribute the FDK AAC Codec
  46 software or your modifications thereto.
  47
  48 Your modified versions of the FDK AAC Codec must carry prominent notices stating that you changed the software
  49 and the date of any change. For modified versions of the FDK AAC Codec, the term
  50 "Fraunhofer FDK AAC Codec Library for Android" must be replaced by the term
  51 "Third-Party Modified Version of the Fraunhofer FDK AAC Codec Library for Android."
  52
  53 3.    NO PATENT LICENSE
  54
  55 NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without limitation the patents of Fraunhofer,
  56 ARE GRANTED BY THIS SOFTWARE LICENSE. Fraunhofer provides no warranty of patent non-infringement with
  57 respect to this software.
  58
  59 You may use this FDK AAC Codec software or modifications thereto only for purposes that are authorized
  60 by appropriate patent licenses.
  61
  62 4.    DISCLAIMER
  63
  64 This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright holders and contributors
  65 "AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, including but not limited to the implied warranties
  66 of merchantability and fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
  67 CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary, or consequential damages,
  68 including but not limited to procurement of substitute goods or services; loss of use, data, or profits,
  69 or business interruption, however caused and on any theory of liability, whether in contract, strict
  70 liability, or tort (including negligence), arising in any way out of the use of this software, even if
  71 advised of the possibility of such damage.
  72
  73 5.    CONTACT INFORMATION
  74
  75 Fraunhofer Institute for Integrated Circuits IIS
  76 Attention: Audio and Multimedia Departments - FDK AAC LL
  77 Am Wolfsmantel 33
  78 91058 Erlangen, Germany
  79
  80 www.iis.fraunhofer.de/amm
  81 amm-info@iis.fraunhofer.de
  82 ----------------------------------------------------------------------------------------------------------- */
  83
  84 /*****************************  MPEG-4 AAC Decoder  **************************
  85
  86    Author(s):   Josef Hoepfl
  87    Description: individual channel stream info
  88
  89 ******************************************************************************/
  90
  91 #include "channelinfo.h"
  92 #include "aac_rom.h"
  93 #include "aac_ram.h"
  94 #include "FDK_bitstream.h"
  95
  96
  97 AAC_DECODER_ERROR IcsReadMaxSfb (
  98         HANDLE_FDK_BITSTREAM bs,
  99         CIcsInfo *pIcsInfo,
 100         const SamplingRateInfo *pSamplingRateInfo
 101         )
 102 {
 103   AAC_DECODER_ERROR ErrorStatus = AAC_DEC_OK;
 104   int nbits;
 105
 106   if (IsLongBlock(pIcsInfo)) {
 107     nbits = 6;
 108     pIcsInfo->TotalSfBands = pSamplingRateInfo->NumberOfScaleFactorBands_Long;
 109   } else {
 110     nbits = 4;
 111     pIcsInfo->TotalSfBands = pSamplingRateInfo->NumberOfScaleFactorBands_Short;
 112   }
 113   pIcsInfo->MaxSfBands = (UCHAR) FDKreadBits(bs, nbits);
 114
 115   if (pIcsInfo->MaxSfBands > pIcsInfo->TotalSfBands){
 116     ErrorStatus = AAC_DEC_PARSE_ERROR;
 117   }
 118
 119   return ErrorStatus;
 120 }
 121
 122
 123
 124 AAC_DECODER_ERROR IcsRead(HANDLE_FDK_BITSTREAM bs,
 125                           CIcsInfo *pIcsInfo,
 126                           const SamplingRateInfo* pSamplingRateInfo,
 127                           const UINT flags)
 128 {
 129   AAC_DECODER_ERROR ErrorStatus = AAC_DEC_OK;
 130
 131   pIcsInfo->Valid = 0;
 132
 133   if (flags & AC_ELD){
 134     pIcsInfo->WindowSequence = OnlyLongSequence;
 135     pIcsInfo->WindowShape = 0;
 136   }
 137   else {
 138     if ( !(flags & (AC_USAC|AC_RSVD50)) ) {
 139       FDKreadBits(bs,1);
 140     }
 141     pIcsInfo->WindowSequence = (UCHAR) FDKreadBits(bs,2);
 142     pIcsInfo->WindowShape = (UCHAR) FDKreadBits(bs,1);
 143     if (flags & AC_LD) {
 144       if (pIcsInfo->WindowShape) {
 145         pIcsInfo->WindowShape = 2; /* select low overlap instead of KBD */
 146       }
 147     }
 148   }
 149
 150   /* Sanity check */
 151   if ( (flags & (AC_ELD|AC_LD)) && pIcsInfo->WindowSequence != OnlyLongSequence) {
 152     pIcsInfo->WindowSequence = OnlyLongSequence;
 153     ErrorStatus = AAC_DEC_PARSE_ERROR;
 154     goto bail;
 155   }
 156
 157   ErrorStatus = IcsReadMaxSfb(bs, pIcsInfo, pSamplingRateInfo);
 158   if (ErrorStatus != AAC_DEC_OK) {
 159     goto bail;
 160   }
 161
 162   if (IsLongBlock(pIcsInfo))
 163   {
 164     if ( !(flags & (AC_ELD|AC_SCALABLE|AC_BSAC|AC_USAC|AC_RSVD50)) ) /* If not ELD nor Scalable nor BSAC nor USAC syntax then ... */
 165     {
 166       if ((UCHAR)FDKreadBits(bs,1) != 0 ) /* UCHAR PredictorDataPresent */
 167       {
 168         ErrorStatus = AAC_DEC_UNSUPPORTED_PREDICTION;
 169         goto bail;
 170       }
 171     }
 172
 173     pIcsInfo->WindowGroups = 1;
 174     pIcsInfo->WindowGroupLength[0] = 1;
 175   }
 176   else
 177   {
 178     INT i;
 179     UINT mask;
 180
 181     pIcsInfo->ScaleFactorGrouping = (UCHAR) FDKreadBits(bs,7);
 182
 183     pIcsInfo->WindowGroups = 0 ;
 184
 185     for (i=0; i < (8-1); i++)
 186     {
 187       mask = 1 << (6 - i);
 188       pIcsInfo->WindowGroupLength[i] = 1;
 189
 190       if (pIcsInfo->ScaleFactorGrouping & mask)
 191       {
 192         pIcsInfo->WindowGroupLength[pIcsInfo->WindowGroups]++;
 193       }
 194       else
 195       {
 196         pIcsInfo->WindowGroups++;
 197       }
 198     }
 199
 200     /* loop runs to i < 7 only */
 201     pIcsInfo->WindowGroupLength[8-1] = 1;
 202     pIcsInfo->WindowGroups++;
 203   }
 204
 205
 206 bail:
 207   if (ErrorStatus == AAC_DEC_OK)
 208     pIcsInfo->Valid = 1;
 209
 210   return ErrorStatus;
 211 }
 212
 213
 214 /*
 215   interleave codebooks the following way
 216
 217     9 (84w) |  1 (51w)
 218    10 (82w) |  2 (39w)
 219   SCL (65w) |  4 (38w)
 220     3 (39w) |  5 (41w)
 221             |  6 (40w)
 222             |  7 (31w)
 223             |  8 (31w)
 224      (270w)     (271w)
 225 */
 226
 227
 228 /*
 229   Table entries are sorted as following:
 230   | num_swb_long_window | sfbands_long | num_swb_short_window | sfbands_short |
 231 */
 232 AAC_DECODER_ERROR getSamplingRateInfo(
 233         SamplingRateInfo *t,
 234         UINT samplesPerFrame,
 235         UINT samplingRateIndex,
 236         UINT samplingRate
 237         )
 238 {
 239   int index = 0;
 240
 241
 242   t->samplingRateIndex = samplingRateIndex;
 243   t->samplingRate = samplingRate;
 244
 245   switch (samplesPerFrame) {
 246   case 1024:
 247     index = 0;
 248     break;
 249   case 960:
 250     index = 1;
 251     break;
 252   case 512:
 253     index = 3;
 254     break;
 255   case 480:
 256     index = 4;
 257     break;
 258
 259   default:
 260     return AAC_DEC_UNSUPPORTED_FORMAT;
 261   }
 262
 263   t->ScaleFactorBands_Long = sfbOffsetTables[index][samplingRateIndex].sfbOffsetLong;
 264   t->ScaleFactorBands_Short = sfbOffsetTables[index][samplingRateIndex].sfbOffsetShort;
 265   t->NumberOfScaleFactorBands_Long = sfbOffsetTables[index][samplingRateIndex].numberOfSfbLong;
 266   t->NumberOfScaleFactorBands_Short = sfbOffsetTables[index][samplingRateIndex].numberOfSfbShort;
 267
 268   if (t->ScaleFactorBands_Long == NULL || t->NumberOfScaleFactorBands_Long == 0) {
 269     return AAC_DEC_UNSUPPORTED_FORMAT;
 270   }
 271
 272   FDK_ASSERT(t->ScaleFactorBands_Long[t->NumberOfScaleFactorBands_Long] == samplesPerFrame);
 273   FDK_ASSERT(t->ScaleFactorBands_Short == NULL || t->ScaleFactorBands_Short[t->NumberOfScaleFactorBands_Short]*8 == samplesPerFrame);
 274
 275   return AAC_DEC_OK;
 276 }